This invention relates to strap segments adapted for forming a loop about material to be tied and for forming a sealless strap connection between overlapping strap ends of the segment. Such strap is typically made of relatively stiff sheet material, i.e., metal strap, and the like.
It is known to provide sealless connections between strap ends in the form of an array of longitudinally spaced joint elements. A common form of such a connection utilizes a central tongue provided with lateral wing extensions partly along the opposite ends of the tongue. Representative prior art patents of this form of joint in this particular field of art are U.S. Pat. Nos. 180,910 to Omstead, 1,606,331 to Anderson, 2,268,339 and 2,276,988 to Leslie, 3,137,047 to Mosey, 3,177,538 to Timmerbeil, and 3,188,706 to Partridge. A form of sealless strap connection wherein a relatively higher strength at the connection is realized and lateral pull out action is avoided, or minimized is taught in U.S. Pat. No. 3,303,541 to Beach.
In many of the aforesaid instances, the connection is maintained only when the joined overlapping ends are kept under tension. If tension is temporarily released on the connection and/or if the overlapped strap ends are longitudinally shifted relative to each other (e.g., if the joint is accidentally bumped), then the connection may be released and the strap ends would separate. Problems of accidental disengagement of the connection are especially significant during the time the strap loop ends are being connected about a compressed bale before the bale is subsequently allowed to expand against the loop.
Various types of sealless strap connection anti-disengagement mechanisms are known. One form of such a sealless strap connection utilizes opposed shoulders displaced from the respective planes of the overlapped lengths of strap which are shaped to interlock with each other and an integral abutment means comprising juxtaposed protuberances shaped to irreversibly override each other while the opposed shoulders are moved into interlocking position and present opposed stops when the shoulders interlock with each other. Such a joint is shown in the U.S. patent to Larry J. Simmons, U.S. Pat. No. 3,935,616.
Sealless strap connections which utilize opposed shoulders displaced from the respective planes of the overlapped lengths of strap which are shaped to interlock with each other, as disclosed in the above-discussed Simmons patent, and which further have anti-disengagement abutment means as an integral part of one or more of the interlocking shoulders are disclosed in the U.S. Pat. No. 4,031,594 to Cepuritis, in the U.S. Pat. No. 4,048,697 to Duenser, and in the U.S. Pat. No. 4,062,086 to Wojcik. All of these patents are assigned to the assignee of the present application.
Other sealless strap connections are known in which some degree of anti-disengagement is effected by specific structures. For example, in the U.S. Pat. No. 161,409 to Hardman an interlocking joint element connection is provided which includes a number of tongues projecting from one strap end and which are received in slots in the other strap end. A reverse tongue is provided to prevent the other connection tongues from springing out of their slots by a sudden pressure or force on the strap.
In the U.S. Pat. No. 203,255 to Ewing, a sealless connection is provided by engaging slots in overlapping ends of a strap loop. Upstanding tongues are provided on each end of the strap for being received in perforations on the other end of the strap to prevent disengagement.
The U.S. Pat. No. 2,035,351 to Taylor shows tongues and receiving slots in overlapping strap end portions, similar to the configuration disclosed in the abovediscussed Ewing patent.
Other forms of sealless strap connections have been devised which prevent, to some degree, disengagement but which are more cumbersome to use than many of the above-described connections. The U.S. Pat. No. 165,407 to Dawson shows a strap segment having apertures on one end for receiving lugs projecting from the other end of the strap. The U.S. Pat. No. 2,276,988 to Leslie, discussed above, discloses an interlocking slit-type joint in which the overlapping strap ends are restrained against reverse movement by the formation of a deformation in the overlapping strap lengths after the strap lengths are interlocked. A special tool is required to create the deformations.
Another type of sealless connection with a lock catch feature which affords some degree of disengagment protection is illustrated in the U.S. Pat. No. 3,426,392 to Timmerbeil. The lock catch is an especially conformed combination of angled slits and is located between two interlocking fastening catches.
In use, a strap segment is typically looped around a material or package to be tied and the sealless connection is formed in the overlapping strap ends. With many types of sealless connections, the strap can be removed from the package or material by disengaging the connected overlapped ends. To do this, the tension in the strap loop must be overcome so that the ends of the strap can be pushed longitudinally relative towards and past each other in the disengaging direction. With such disengageable strap connections, there is a disadvantage. Specifically, when an untensioned strap loop is formed around a compressed package or bale, the loop can be accidentally bumped. This may cause the strap ends to move relative to each other and to become disengaged. Consequently, the various anti-disengagement structures have been developed for such sealless strap connections as set forth in many of the patents discussed above. However, some of the sealless connections that have anti-disengagement structures cannot be easily or readily disengaged by hand. Strap loops connected with such anti-disengagement structures that are not readily disengageable are usually cut or severed when it is desired to release the strap from the bound package or material. Other types of sealless connections with antidisengagement structures do not work as well as desired. Some are difficult to properly assemble, some are difficult to disengage, and some disengage too easily.
It would be beneficial to provide an easily disengageable sealless strap connection with an anti-disengagement structure that would prevent disengagement when the connection was initially being made in a strap loop around a compressed bale before the bale was expanded tight against the strap loop.
It would also be desirable to provide a sealless connection with an anti-reverse or anti-disengagement structure which could be easily disengaged by moving the joint region of the strap loop in a certain manner to render the anti-disengagement structure ineffective prior to moving the overlapping strap loop ends in the disengaging direction.